/**
 * Copyright (c) 2010 by Kevin Bierhoff.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *    1. Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *    2. Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *    3. Neither the names of the authors nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.googlecode.syper.test.javasyp.logic;

import com.googlecode.syper.anno.Excl;
import com.googlecode.syper.anno.Imm;
import com.googlecode.syper.anno.Invariant;
import com.googlecode.syper.anno.NullChecks;
import com.googlecode.syper.anno.Old;
import com.googlecode.syper.anno.Pred;
import com.googlecode.syper.anno.Result;
import com.googlecode.syper.anno.ReturnExcl;

import edu.cmu.cs.crystal.annotations.FailingTest;
import edu.cmu.cs.crystal.annotations.UseAnalyses;

/**
 * @author kevin
 * @since Feb 23, 2010
 */
@NullChecks
@FailingTest(2)
@UseAnalyses("SymbolicChecker")
public class CounterFail implements Invariant {
	
	private int value;
	
	public CounterFail() {
		this(0);
		Pred.ensures(value == 0);
	}

	public CounterFail(final int initial) {
		Pred.requires(0 <= initial);
		this.value = initial;
		Pred.ensures(value == initial);
	}
	
	@Excl(mod = "value")
	public int inc() {
		@Result final int result;
		@Old final int prev;
		excl: {
			prev = value;
			result = prev + 1;
			value = result;
			Pred.ensures(value == result & value == prev + 1);
		}
		return result;
	}

	@Imm
	public int get() {
		@Result final int result;
		imm: {
			result = value;
			Pred.ensures(value == result);
		}
		return result;
	}
	
	@Imm
	@Override
	public boolean inv() {
		imm: return 0 <= value;
	}
	
	public static void testFailingCounter(@Excl CounterFail c) {
		Pred.requires(c != null && c.value == 0);
		int last = c.get();
		last = c.inc();
		last = c.inc();
		last = c.inc();
		// last must be 3 so < 3 should fail
		assert last < 3;
	}

	@ReturnExcl
	public static CounterFail testFailingConstructor() {
		// pre-condition violated
		return new CounterFail(-1);
	}

}
